Contraction joint



July 25, 1939. A. cARNlE CONTRACTION -JOINT Filed Jan. 3, 1938 Patented July 25, 1939 e UNITED STATES PATENT OFFICE CONTRACTION JOINT Alexander Carne, Youngstown, Ohio,l assgnor to Truscon Steel Company, Youngstown, Ohio, a corporation of Michigan Application January 3, 1938, Serial No. 183,210

2 Claims. (Cl. 94-18) This invention relates to contraction joints used Figure 3 is a fragmentary elevation of the plate in concrete roads or pavements for the purpose of showing the rib produced by the gathered metal directing or vcontrolling the formation of a `relaat the bottom portion of the plate.rv

tively small crackV at predetermined points upon Figure 4 is a vertical Ysectionalviewv takenjon 5 the contraction or setting of the pavement after the line 4-4 of Figure 3. v 5"' it is poured. v Figure 5 is a vertical sectional view taken on In the building of concrete roadways, one or the line,5-5 ofFigure 3. more contraction jointsare placed transversely Figure 6` is a detail horizontal sectional view of the roadway in definite relation to the expantaken on the line 6 6 of Figure 3. 10 sion joints, for example, atpre-determined in- Similardreference characters designateV corre- 10" tervals'between the expansion joints, depending sponding parts throughout the several gures of y upon the size of the slab. Also, while contraction the drawing. v joints may be of the longitudinal or center type, According to the embodiment of the invention nevertheless, the present invention is directed illustrated, the same includes in its organization 15 more especially to joints of the transverse type a plate of metal of suitable length and height which must be curved to conform to the crown of as well as of suitable gage, designated generally the road. f as A having a plain upper portion I anda foot Accordingly; va primary object of the invention portion or base 2 formed by folding vover the is to provide a metal contraction joint having metal at the bottom ofthe plate. in right angular features of construction whichfpe'rmit it to stand relation to the major plane of the plate to 20 erect across the roadway and at the same time provide foot or base flanges extending on both coincide with apredetermined crown specified for sides of theA plane of thedplat'e. Thus, a subthe roadway. That is to say; the present invenstantial support 4is provided formaintaining the tion contemplates the provision of a contractionv plate in a normally vertical position during the joint having a base intended to rest on the subpreliminary work in placing it in the roadway, 25 grade of the road to be poured, in such away as although it will, of course, beV understood that to support the plate or web thereof in a vertical should suitable fastenings be required under position, the metal of the plate as well as the .special specifications, the base may be secured to base being crimped or gathered crosswise at in-V the sub-grade in any suitable manner as by stakes tervals, in a predetermined direction and amount, or spikes without altering the fact that primarily 30 150 insure the PrODer curvature 0f the plate'to coI-Y the base 2 is intended to provide means for norrespond to the specified crown of the finished road mally holding the plate upright. An additional slabs. function of the base 2 vis to provide means for A further object of the invention is to provide anchoring the joint in theroadway. That is to a contraction joint having a metallic seal in the eey,A the base is embedded beneath the Slabs to 35 formV of a cap plate fitted t0 the upper edge prevent the same from workingupvvard.v l thereof, the Said Cap plate being utilized to form f Atl spaced intervals throughout the length of a more or less flexible joint between the concrete the plate A, there are provided a plurality of sepaslabs permitting one to move relative to the other Y rate vertical utes or erimps 3 which partake of When neCeSSary, and further preventing moisture the nature of offset ribs at one side of the plate 40 d or water from entering the joint. and preferably extend'for more than half Vof the With the above and other objects in view which height thereof. These oisets merge, at their Will more readily appear eS the nature 0f the irllower ends with the horizontal offset portions or vention is better understood, the same consists in ribs 3a which extend transversely throughout the the novel construction, combination and arrangefull width of the base 2 as indicated in Figure 4. 45

' ments of parts hereinafter more fully described, Therefore, the eiTect of crimping or gathering the illustrated and Claimed metal of both the plate and the base is to give A preferred and practical embodiment of the the entire structure a predetermined or set curvainVeHtiOrl iS SllOWD in the eCCOmDanyirlg drawing ture in accordance with a specified installation. in which: The elements 3 are preferably flared down- 50 Figure 1 is a transverse sectional View of a Wardly, that is, are narrow at the top and wider roadway illustrating the application of the inat the bottom, or in other words, the side edges vention. v 4 diverge downwardly approximately from a point Figure 2 is a detail perspective View further il- 5 between the horizontal center of the plate and lustrating the application of the invention. the top edge thereof to a point 6 located in the 55 base 2.

The face 1 of each element 3 is substantially of uniform width throughout but the divergent relation of the sides 4 has the effect of gathering the metal of the plate progressively from the point 5 toward the bottom of the plate so as to shorten the length and thus curve the bottom edge portion of the plate while causing the upper edge to assume a corresponding curvature. The number, width and the spacing of the ribs or equivalent elements 3 varies with different specications.

The vertical height of the plate A is preferably less than the height of the completed road slabs S and S' as will be apparent from Figure 2. The top edge of the plain portion I of the plate A may, if the specications require, be provided with a cap member C, which is suiiciently flexible to readily adapt itself, and conform,.to the curvature of the plate of the joint. This cap portion consists of the body 8 folded upon itself to provide for telescopically receiving the upper plain edge portion I of the plate, and the lower edges of said body 8 are provided with laterally outstanding wings 9 for embedment in the concrete slabs, which embedment may be enhanced by the provision of the locking or keying ribs it. The body V8 is preferably held interlocked with the upper portion of the plate A by indentations or buttons 8a. which engage With mating depressions in the plate.

When the contraction joint is installed with the cap C thereon it will be apparent that the wings 9 are embedded in the concrete and when the slabs move in contracting, the wings will cause the folds of the body to separate with the top of the fold serving as a hinging axis, and the wings 9 themselves will prevent water or moisture from seeping down in the space between the slabs formed by the body of the plate A.

In installations Where the cap plate C is not required or specied it will, of course, be understood that the space at the upper edges of the slab may be lled with bituminous composition to render the joint Weather proof.

In practice, after the contraction joint has been formed as described and shown in Figures 3-6 inclusive, it is laid transversely on the sub-grade of the roadway between the usual road forms, and because of the horizontal base 2, the plate will assume a normally upright position. Where the cap C is desired, the same is applied to the upper edge of the plate and the concrete for the slabs is poured, so that after the slabs have been made the entire contraction joint is embedded in the roadway as' indicated in Figure 2.

From the foregoing, it will be apparent that applicants invention comprises a contraction joint including a single vertical plate or web A whose upper portion remains plain or uncrimped while the bottom portion thereof including the horizontal base 2 is crimped or fluted at spaced intervals to cause gathering of the metal below the central portion of the plate thereby to impart the desired curvature to boththe top and bottom edges of the joint. The displacements of the flutes or ribs 3 and 3a in the manner shown adequately provides for shortening the length of the lower portion of the plate while causing the upper edge to also assume a curvature on the selected radius.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will, of course, be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

I claim; Y

1. A contraction joint including a single substantially vertical plate and a horizontal base, said plate being provided with a plurality of vertical crimps laterally spaced below its upper edge while said upper edge remains straight to compel a straight line of cleavage transversely ofthe road, and said base being provided with upwardly pressed crimps to prevent the base from rocking and provide a firm support for the plate, said crimps in the base being located at the bottom of the crimps in the plate and together there with providing means for shortening the lower chord of the plate and to impart a curvature to the upper edge thereof on substantially the same radius as the curvature of the base.

2. A contraction joint comprising a single vertical plate portion having the bottom edge thereof folded at right angles thereto to provide flanges extending on both sides of the vertical plane of the plate to constitute a firm base on which the joint rests and to maintain the plate vertical, and crimps formed in the plate and base, said crimps in the plate extending vertically thereof and having downwardly divergent side portions where they are pressed from the plate to prevent buckling and also provide for shortening the lower chord of the plate vwhile leaving the top chord straight to compel a straight line of cleavage transversely of the road, and said crimpsl in the base being formed at the upper side thereof and corresponding in width to the width of the bottom of the crimps inthe plate and extending across said base.

ALEXANDER CARNIE. 

